Traditionally, cross-site scripting is a security vulnerability found within Internet accessible content. A cross-site scripting vulnerability may be exploited by a third party to acquire personal data or to trick an end user into performing a malicious action. For example, a cross-site scripting vulnerability may be exploited to steal an end user's Internet cookies, which may allow for the third party to access the end user's account associated with the Internet cookie. Similarly, a cross-site scripting vulnerability may allow a third party to trick an end user into accessing or disseminating malware.
Previously, cross-site scripting has been prevented, in part, by sanitizing content that may contain encoded content that may be communicated to an end user. Unfortunately, the sanitizing process only provides relief for those vulnerabilities known to exist or known to potentially exist. If a third party identifies a new vulnerability and exploits that vulnerability before the Internet content is encoded, an end user may fall victim to a cross-site scripting attack.